Pathogenic Detection by Metagenomic Next-Generation Sequencing in Osteoarticular Infections

The diagnostic value of bronchoalveolar lavage fluid metagenomic next-generation sequencing in critically ill patients with respiratory tract infections

Metagenomic next-generation sequencing (mNGS) is an unbiased and rapid method for detecting pathogens. This study enrolled 145 suspected severe pneumonia patients who were admitted to the Affiliated Hospital of Jining Medical University. This study primarily aimed to determine the diagnostic performance of mNGS and conventional microbiological tests (CMTs) using bronchoalveolar lavage fluid samples for detecting pathogens. Our findings indicated that mNGS performed significantly higher sensitivity (97.54% vs 28.68%, P < 0.001), coincidence (90.34% vs 35.17%, P < 0.001), and negative predictive value (80.00% vs 13.21%, P < 0.001) but performed lower specificity than CMTs (52.17% vs 87.5%, P < 0.001). Streptococcus pneumoniae as the most common bacterial pathogen had the largest proportion (22.90%, 30/131) in this study. In addition to bacteria, fungi, and virus, mNGS can detect a variety of atypical pathogens such as Mycobacterium tuberculosis and non-tuberculous. Mixed infections were common in patients with severe pneumonia, and bacterial-fungal-viral-atypical pathogens were the most complicated infection. After adjustments of antibiotics based on mNGS and CMTs, the clinical manifestation improved in 139 (95.86%, 139/145) patients. Our data demonstrated that mNGS had significant advantage in diagnosing respiratory tract infections, especially atypical pathogens and fungal infections. Pathogens were detected timely and comprehensively, contributing to the adjustments of antibiotic treatments timely and accurately, improving patient prognosis and decreasing mortality potentially.IMPORTANCEMetagenomic next-generation sequencing using bronchoalveolar lavage fluid can provide more comprehensive and accurate pathogens for respiratory tract infections, especially when considering the previous usage of empirical antibiotics before admission or complicated clinical presentation. This technology is expected to play an important role in the precise application of antimicrobial drugs in the future.

Improved cure rate of periprosthetic joint infection through targeted antibiotic therapy based on integrated pathogen diagnosis strategy

Objectives

This study aimed to determine whether combined of pathogen detection strategies, including specimen acquisition, culture conditions, and molecular diagnostics, can improve treatment outcomes in patients with periprosthetic joint infections (PJI).

Methods

This retrospective study included suspected PJI cases from three sequential stages at our institution: Stage A (July 2012 to June 2015), Stage B (July 2015 to June 2018), and Stage C (July 2018 to June 2021). Cases were categorized into PJI and aseptic failure (AF) groups based on European Bone and Joint Infection Society (EBJIS) criteria. Utilization of pathogen diagnostic strategies, pathogen detection rates, targeted antibiotic prescription rates, and treatment outcomes were analyzed and compared across the three stages.

Results

A total of 165 PJI cases and 38 AF cases were included in this study. With the progressive implementation of the three optimization approaches across stages A, B and C, pathogen detection rates exhibited a gradual increase (χ2 = 8.282, P=0.016). Similarly, utilization of targeted antibiotic therapy increased stepwise from 57.1% in Stage A, to 82.3% in Stage B, and to 84% in Stage C (χ2 = 9.515, P=0.009). The 2-year infection control rate exceeded 90% in both stages B and C, surpassing stage A (71.4%) (χ2 = 8.317, P=0.011). Combined application of all three optimized protocols yielded the highest sensitivity of 91.21% for pathogen detection, while retaining higher specificity of 92.11%.

Conclusion

The utilization of combined pathogen diagnostic strategies in PJI can increase pathogen detection rates, improve targeted antibiotic prescription, reduce the occurrence of antibiotic complications, and achieve better treatment outcomes.

Diagnostic Role of Metagenomic Next-Generation Sequencing in Tubercular Orthopedic Implant-Associated Infection

Objective

The diagnosis of tubercular orthopedic implant-associated infection (TB-IAI) is challenging. This study evaluated the value of metagenomic next-generation sequencing (mNGS) for the diagnosis of TB-IAI and developed a standardized diagnostic procedure for TB-IAI.

Methods

The records of all patients with TB-IAI diagnosed and treated at our institution between December 2018 and September 2022 were retrospectively reviewed. Patient demographic characteristics, medical history, laboratory test, microbial culture, histopathology, and mNGS results, and time to diagnosis were recorded. The diagnostic efficiency of mNGS for TB-IAI was assessed by comparing the results and diagnostic time with that of other diagnostic modalities.

Results

Ten patients were included in the analysis, including eight with prosthetic joint infections and two with fracture-related infections. The mNGS positivity rate was 100% (10/10), which was higher than that of TB-antibody (11%, 1/9), real-time quantitative polymerase chain reaction (22%, 2/9), T-SPOT.TB (25%, 2/8), purified protein derivative (50%, 4/8), microbial culture (50%, 5/10), and histopathology (20%, 2/10). mNGS shortened the time to diagnosis of TB-IAI. A standardized diagnostic procedure for TB-IAI was developed based on the findings.

Conclusion

mNGS is useful for the diagnosis of TB-IAI. mNGS is recommended in cases where it is difficult to identify a pathogen using routine diagnostic tests. The standardized diagnostic procedure might improve TB-IAI diagnosis.

Importance

TB-IAI is a rare infection, which occurs after orthopedic surgery and hard to diagnose microbiologically. mNGS is a new detection technique not yet discussed in current literature as a means for TB-IAI diagnostics. Here we describe a cohort of patients with TB-IAI diagnosed by mNGS show high efficiency of mNGS for detection of this pathology and present a clinical algorithm supplementing conventional methods for TB-IAI assessment.

Pathogen detection in suspected spinal infection: metagenomic next-generation sequencing versus culture

PURPOSE

The aim is to compare the pathogen detection performance of metagenomic next-generation sequencing (mNGS) and the culturing of percutaneous needle biopsy samples obtained from an individual with a suspected spinal infection.

METHODS

A retrospective study of 141 individuals with a suspected spinal infection was conducted, and mNGS was performed. The microbial spectra and detection performance between mNGS and the culturing-based method were compared, and the effects of antibiotic intervention and biopsy on the detection performance were assessed.

RESULTS

The microorganisms isolated most commonly via the culturing-based method were Mycobacterium tuberculosis (n = 21), followed by Staphylococcus epidermidis (n = 13). The most common microorganisms detected via mNGS were Mycobacterium tuberculosis complex (MTBC) (n = 39), followed by Staphylococcus aureus (n = 15). The difference in the type of detected microorganisms between culturing and mNGS was observed only in Mycobacterium (P = 0.001). mNGS helped identify potential pathogens in 80.9% of cases, which was significantly higher than the positivity rate of 59.6% observed for the culturing-based method (P < 0.001). Moreover, mNGS had a sensitivity of 85.7% (95% CI, 78.4% to 91.3%), a specificity of 86.7% (95% CI, 59.5% to 98.3%), and sensitivity gains of 35% (85.7% vs. 50.8%; P < 0.001) during culturing, while no differences were observed in the specificity (86.7% vs. 93.3%; P = 0.543). In addition, antibiotic interventions significantly lowered the positivity rate of the culturing-based method (66.0% vs. 45.5%, P = 0.021) but had no effects on the results of mNGS (82.5% vs. 77.3%, P = 0.467).

CONCLUSION

The use of mNGS could result in a higher detection rate compared to that observed with the culturing-based method in an individual with spinal infection and is particularly valuable for evaluating the effects of a mycobacterial infection or previous antibiotic intervention.

Composition of pathogenic microorganism in chronic osteomyelitis based on metagenomic sequencing and its application value in etiological diagnosis

BACKGROUND

Traditionally, conventional microbiological culture methods have been used to detect pathogenic microorganisms in chronic osteomyelitis. However, these methods have been found to have a low detection rate, complicating the precise guidance of infection treatment. This study employed metagenomic next-generation sequencing (mNGS) to detect these microorganisms in chronic osteomyelitis with three main objectives: 1). Gain a deeper understanding of the composition of pathogenic microorganisms in chronic osteomyelitis. 2). Compare the microbial detection rates between mNGS and the standard culture methods used in laboratories to enhance the effectiveness of the traditional culture methods. 3). Explore the potential of mNGS in etiological diagnosis.

METHODS

Fifty clinically confirmed intraoperative bone tissue samples of chronic osteomyelitis from January 2021 to December 2021 were collected and subjected to mNGS and microbiological testing, respectively. The orthopaedic surgeon combined clinical manifestations and related examinations to determine the causative pathogens.

RESULTS

The culture method obtained 29 aerobic and parthenogenic anaerobic bacteria, 3 specific anaerobic bacteria, and 1 yeast-like fungus. Thirty-six aerobic and parthenogenic anaerobic bacteria, 11 specific anaerobic bacteria, and 1 yeast-like fungus were obtained by mNGS, and 2 Mycobacterium tuberculosis(MTB) strains were detected. However, there was no significant difference in the overall positive detection rate between mNGS and the culture method (P = 0.07), and the two were not statistically significant in detecting aerobic and partly anaerobic bacteria (P = 0.625). But, mNGS was significantly superior to culture in detecting anaerobic bacteria and Mycobacterium tuberculosis (P<0.05).

CONCLUSIONS

The mNGS method has enhanced our understanding of the distribution of pathogenic microorganisms in chronic osteomyelitis. Traditional culture methods help isolate and cultivate aerobic and facultative anaerobic bacteria, and fungi, and are also utilized for antibacterial drug sensitivity tests. However, mNGS has shown superior capabilities in detecting anaerobic bacteria, MTB, and mixed infection bacteria. This finding offers invaluable guidance for improving laboratory microbial culture and detection conditions. Hence, mNGS should be judiciously used for chronic osteomyelitis, and PCR can be implemented for certain difficult-to-culture microorganisms, such as MTB.

A case report on Mycobacterium houstonense infection after total hip arthroplasty

BACKGROUND

Mycobacterium houstonense is a category of rapidly growing mycobacteria that is gram-positive, acid-fast, polycrystalline, and non-spore-forming. There have been few reports of human infection caused by Mycobacterium houstonense worldwide.

CASE PRESENTATION

We present a case of chronic periprosthetic joint infection caused by Mycobacterium houstonense in an elderly female patient. The patient developed signs of infection after undergoing total hip arthroplasty. Despite receiving antibiotic treatment and revision surgery, the signs of infection recurred repeatedly. Multiple bacterial cultures during the treatment period were negative. Later, we identified the pathogenic bacteria Mycobacterium houstonense through mNGS testing, isolated the bacteria from the ultrasonically centrifuged fluid of the prosthesis and obtained drug sensitivity results. Finally, we performed a revision surgery and treated the patient with moxifloxacin and clindamycin. After treatment, the patient did not show signs of infection recurrence during 24 months of follow-up.

CONCLUSION

Through a relevant literature search, we believe that Mycobacterium houstonense may show higher sensitivity to amikacin and quinolone antibiotics. Additionally, clarifying occult infection sources through methods such as gene testing will improve the diagnosis and treatment of periprosthetic joint infection.

Optimal Perioperative Antimicrobial Management Strategies of Kidney Transplant Recipients Guided by Metagenomic Next-Generation Sequencing of Deceased Donors' Microbiology Samples

Background

There is no consensus on the optimal use of perioperative antibiotics prophylaxis after kidney transplantation, but there is a common trend to limit the duration of antibiotic use worldwide. Metagenomic next-generation sequencing (mNGS) has emerged as a novel technology for pathogen detection in clinical practice due to its noninvasive, rapid, precise and high susceptibility to detect infectious pathogens. However, data are lacking on whether mNGS analyses could be used to detect pathogens and guide anti-infection regimens in kidney transplant donors and recipients.

Methods

We conducted a retrospective study to review all clinic data of mNGS and traditional laboratory methods (TMs) for pathogen detection in kidney transplant recipients and their corresponding deceased donors from August 1, 2021 to October 30, 2022 in our center.

Results

A total of 57 donors and 112 of their corresponding recipients were included. The antimicrobial strategy mainly depended on mNGS results combined with traditional pathogen culture and clinical conditions. The percentages of positive pathogen detected by mNGS in blood, urine, bronchoalveolar lavage fluid (BALF) and preservation fluids (PFs) were 50.9% (29/57), 35.1% (20/57), 84.2% (48/57) and 54.4% (31/57) respectively, and were 24.6% (14/57), 15.8% (9/57), 57.9% (33/57) and 14.1% (8/57) respectively when using TMs. mNGS could detected all of pathogens which were detected by TMs. However, samples with negative TMs testing can be additionally detected as positive by mNGS (15/43 in blood, 11/48 in urine, 15/24 in BALF and 23/49 in PFs). Drug resistance genes were detected in 9 donors by mNGS,which were consistent with 6 donors by TMs. There was only one case of donor-derived infection in this study.

Conclusion

This study showed that it is effective to combine mNGS with traditional pathogen detection methods and clinical features to develop optimal perioperative antimicrobial management strategies for deceased donor kidney transplantation.

Multiplex PCR-based next generation sequencing as a novel, targeted and accurate molecular approach for periprosthetic joint infection diagnosis

Objectives

Periprosthetic joint infection (PJI) diagnosis remains challenging, and the identification of the causative microorganism is, by far, the most important aspect. Here, we use multiple PCR-based targeted next-generation sequencing (tNGS) to detect pathogens in PJI. To explore 1. the ability of targeted next-generation sequencing (tNGS) to detect pathogens in PJI; 2. the consistency of tNGS, metagenomic NGS (mNGS), and culture results; and 3. the ability of tNGS to detect drug resistance genes in PJI.

Methods

PJI was diagnosed according to the Musculoskeletal Infection Society (MSIS) criteria. The microorganisms were detected by culture, mNGS and tNGS to compare the diagnostic effectiveness of the three methods for PJI and to compare their consistency in detecting microorganisms. Drug resistance genes were detected using tNGS. The costs and turnaround times of mNGS and tNGS were compared.

Results

Forty-three patients with PJI, 21 patients without PJI and 10 negative control cases were included. The culture, tNGS, and mNGS sensitivities for PJI diagnosis were 74.41%, 88.37%, and 93.02%, respectively, with no significant differences. The specificities were 90.48%, 95.24%, and 95.24%, respectively, with no significant differences. tNGS detected drug resistance genes in 37.5% of culture-positive PJIs. tNGS was superior to mNGS for turnaround time (14.5 h vs. 28 h) and cost ($150 vs. $260).

Conclusions

tNGS can effectively identify PJI pathogens and may provide drug resistance information, while tNGS is superior to mNGS regarding cost and turnaround time. A multidisciplinary, multi-technology based algorithm to diagnose PJI is appropriate.

Highlights

298 microorganisms and 86 drug resistance genes were included in the tNGS panel.Diagnostic efficacy of tNGS is not inferior to that of commonly used indicators.tNGS is superior to mNGS in cost and turnaround time.

An update on recent progress of the epidemiology, etiology, diagnosis, and treatment of acute septic arthritis: a review

Acute septic arthritis is on the rise among all patients. Acute septic arthritis must be extensively assessed, identified, and treated to prevent fatal consequences. Antimicrobial therapy administered intravenously has long been considered the gold standard for treating acute osteoarticular infections. According to clinical research, parenteral antibiotics for a few days, followed by oral antibiotics, are safe and effective for treating infections without complications. This article focuses on bringing physicians up-to-date on the most recent findings and discussions about the epidemiology, etiology, diagnosis, and treatment of acute septic arthritis. In recent years, the emergence of antibiotic-resistant, particularly aggressive bacterial species has highlighted the need for more research to enhance treatment approaches and develop innovative diagnosis methods and drugs that might combat better in all patients. This article aims to furnish radiologists, orthopaedic surgeons, and other medical practitioners with contemporary insights on the subject matter and foster collaborative efforts to improve patient outcomes. This review represents the initial comprehensive update encompassing patients across all age groups.

Genetic characterization of human adenoviruses in patients using metagenomic next-generation sequencing in Hubei, China, from 2018 to 2019

Objectives

This study aimed to characterize the genomic epidemiology of human adenoviruses (HAdVs) in Hubei, China, using metagenomic next-generation sequencing (mNGS).

Methods

In total, 25 HAdV-positive samples collected from 21 pediatric patients were sequenced and subjected to mNGS using the NextSeq 550 and GenoLab M sequencing platforms. The metagenomic data were assembled de novo for molecular typing, phylogenetic and recombination analyzes.

Results

We assembled 50 HAdV genomes, 88% (22/25) genomes from GenoLab M, and 84% (21/25) genomes from NextSeq 550 have perfect alignments to reference genomes with greater than 90%. The most fully assembled 25 genomes were categorized into 7 HAdV genotypes, the most abundant of which were HAdV-B3 (9/25) and HAdV-C2 (6/25). Phylogenetic analyzes revealed that the newly isolated HAdV-B3 strains diverged into separate clusters according to their genotypes. Vigilance is needed that HAdV-B3 isolates have begun to form new distinct clusters. High nucleotide identity was observed in the whole genome level within the same HAdV genotypes, while marked differences of three capsid genes across HAdV genotypes were noted. The high nucleotide diversity regions were concordant with the reported hypervariable regions. Further, three recombinant strains were identified: S64 and S71 originated from the parental strains HAdV-B14 and HAdV-B11, and S28 originated from HAdV-C1, HAdV-C5, and HAdV-CBJ113. GenoLab M and NextSeq 550 showed comparable performance with respect to data yield, duplication rate, human ratio, and assembly completeness.

Conclusion

The sequencing quality and assembly accuracy showed that mNGS assembled genomes can be used for subsequently HAdV genotyping and genomic characterization. The high nucleotide diversity of capsid genes and high frequency of recombination events has highlighted the necessity for HAdV epidemiological surveillance in China.

Diagnostic Role of mNGS in Polymicrobial Periprosthetic Joint Infection

OBJECTIVES

The purpose of this study was to explore the clinical value of metagenomic next-generation sequencing (mNGS) in the diagnosis of polymicrobial periprosthetic joint infection (PJI).

METHODS

Patients with complete data who underwent surgery at our hospital between July 2017 and January 2021 for suspected periprosthetic joint infection (PJI), according to the 2018 ICE diagnostic criteria, were enrolled, and all patients underwent microbial culture and mNGS detection, which were performed on the BGISEQ-500 platform. Microbial cultures were performed on two samples of synovial fluid, six samples of tissue, and two samples of prosthetic sonicate fluid for each patient. The mNGS was performed on 10 tissues, 64 synovial fluid samples, and 17 prosthetic sonicate fluid samples. The results of mNGS testing were based on the interpretation of mNGS results in the previous literature and the assertions of microbiologists and orthopedic surgeons. The diagnostic efficacy of mNGS in polymicrobial PJI was assessed by comparing the results of conventional microbial cultures and mNGS.

RESULTS

A total of 91 patients were finally enrolled in this study. The sensitivity, specificity, and accuracy of conventional culture for the diagnosis of PJI were 71.0%, 95.4%, and 76.9%, respectively. The sensitivity, specificity, and accuracy of mNGS for the diagnosis of PJI were 91.3%, 86.3%, and 90.1%, respectively. The sensitivity, specificity, and accuracy of conventional culture for the diagnosis of polymicrobial PJI were 57.1%, 100%, and 91.3%, respectively. mNGS had a sensitivity, specificity, and accuracy of 85.7%, 60.0%, and 65.2%, respectively, for the diagnosis of polymicrobial PJI.

CONCLUSIONS

mNGS can improve the diagnosis efficiency of polymicrobial PJI, and the combination of culture and mNGS is a promising method to diagnose polymicrobial PJI.

Clinical Diagnosis Application of Metagenomic Next-Generation Sequencing of Plasma in Suspected Sepsis

Purpose

We analyzed the clinical concordance of mNGS test results from blood samples and improved the clinical efficiency of mNGS in the diagnosis of suspected sepsis pathogens.

Patients and Methods

In this study, 99 samples of suspected blood flow infection were included for plasma mNGS, and the correlation between mNGS results and blood culture results, serum inflammatory indices, clinical symptoms and antibiotic treatment was analyzed, as well as the comparison with the detection rate of BALF pathogens, as well as the classification of different pathogens in the mNGS results were analyzed.

Results

The mNGS pathogen detection rate was higher than that of traditional blood culture (83.02% vs 35.82%). The rate of the mNGS results being consistent with the clinical diagnosis was also higher than that of traditional blood culture (58.49% vs 20.75%). This study shows that bacteria and fungi are the main pathogens in sepsis, and viral sepsis is very rare. In this study, 32% of sepsis patients were secondary to pneumonia. Compared with the pathogen detection rate using alveolar lavage fluid, the detection rate from plasma mNGS was 62.5%. Samples were also easy to sample, noninvasive, and more convenient for clinical application.

Conclusion

This study shows that compared with blood culture, the detection rate of mNGS pathogen that meets the diagnosis of sepsis is higher. We need a combination of multiple indicators to monitor the early diagnosis and treatment of sepsis.

The diagnostic value of blood metagenomic next-generation sequencing in patients with acute hematogenous osteomyelitis

Aims

This study aims to evaluate the diagnostic value of blood metagenomic next-generation sequencing (mNGS) in detecting pathogens from patients clinically diagnosed as acute hematogenous osteomyelitis (AHO).

Methods

This retrospective study enrolled 66 patients with AHO. The test results of mNGS and bacterial culture on different samples, including blood and puncture fluid samples, from patients with AHO were compared to explore the diagnostic value of blood mNGS. Besides, this study also explored the efficacy of blood mNGS in decision making for antibiotic administration and analyzed the factors associated with the positive result of blood mNGS.

Results

The most common causative pathogens were Staphylococcus and Streptococcus. The sensitivity of blood mNGS (77.3%) was higher than that of blood culture (42.4%) (P<0.001), while the turnaround time of blood mNGS (2.1 ± 0.4 d) is much less than that of blood culture (6.0 ± 2.1 d) (P<0.001). Besides, the sensitivity of blood mNGS tests (77.3%) was slightly lower than that of puncture fluid mNGS (89.4%). Furthermore, detection comparison at pathogen level unravels that blood mNGS might be suitable for diagnosing AHO caused by common pathogens, while puncture fluid mNGS could be considered as preferred examination in diagnosing AHO caused by uncommon pathogens. Finally, three independent factors associated with the true positive result of blood mNGS in patients with AHO were identified, including Gram-positive pathogens (OR=24.4, 95% CI = 1.4-421.0 for Staphylococcus; OR=14.9, 95%CI= 1.6-136.1 for other Gram-positive bacteria), body temperature at sampling time (OR=8.2, 95% CI = 0.6-107.3 for body temperature of >38.5°C; OR=17.2, 95% CI = 2.0-149.1 for patients who were chilling), and no use of antibiotics before sampling (OR=8.9, 95% CI =1.4-59.0).

Conclusion

This is the first report on evaluating and emphasizing the importance of blood mNGS in diagnosing AHO. Blood sample might be an alternative sample for puncture fluid for mNGS, and its extensive application in diagnosing AHO could be expected.

Optimization and standardization of mNGS-based procedures for the diagnosis of Mycoplasma periprosthetic joint infection: A novel diagnostic strategy for rare bacterial periprosthetic joint infection

Introduction

The diagnosis of Mycoplasma periprosthetic joint infection (PJI) is rather difficult due to its rarity and difficult in isolation, there are not standardized diagnostic procedure for Mycoplasma PJI presently. This study aimed to reported a metagenomic next-generation sequencing (mNGS)-based diagnostic strategy for Mycoplasma PJI.

Methods

In the present study, we have reported the largest number of Mycoplasma PJI that were precisely diagnosed by mNGS and verified by optimized microbial culture methods and (or) 16S PCR polymerase chain reaction (PCR).

Results

The positive rate of optimized microbial culture methods and 16S PCR in the detection of Mycoplasma PJI was 57.14% and 71.43%, respectively. The infections were well controlled by targeted treatment in all cases.

Conclusion

The standardized and optimized procedure based on mNGS presented in this study is useful for the diagnosis of Mycoplasma PJI, which might also be provided as a novel diagnostic strategy for rare bacterial PJI.

Diagnostic efficiency of metagenomic next-generation sequencing for suspected spinal tuberculosis in China: A multicenter prospective study

Background

The pathogens of suspected spinal tuberculosis (TB) include TB and non-TB bacteria. A rapid and effective diagnostic method that can detect TB and non-TB pathogens simultaneously remains lacking. Here, we used metagenomic next-generation sequencing (mNGS) to detect the pathogens in patients with suspected spinal TB.

Methods

The enrolled patients with suspected spinal TB were regrouped three times into patients with spinal infection and controls, patients with spinal TB and controls, and patients with non-TB spinal infection and controls. We tested the three groups separately by using mNGS and conventional detection methods.

Results

Ultimately, 100 patients were included in this study. Pathogens were detected in 82 patients. Among the 82 patients, 37 had TB and 45 were infected with other bacteria. In patients with spinal infection, the sensitivity of the mNGS assay was higher than that of culture and pathological examination (p < 0.001, p < 0.001). The specificity of the mNGS assay was not statistically different from that of culture and pathological examination (p = 1.000, p = 1.000). In patients with spinal TB, no statistical difference was found between the sensitivity of the mNGS assay and that of Xpert and T-SPOT.TB (p = 1.000, p = 0.430). The sensitivity of the mNGS assay was higher than that of MGIT 960 culture and pathological examination (p < 0.001, p = 0.006). The specificities of the mNGS assay, Xpert, MGIT 960 culture, and pathological examination were all 100%. The specificity of T-SPOT.TB (78.3%) was lower than that of the mNGS assay (100%; p < 0.001). In patients with non-TB spinal infection, the sensitivity of the mNGS assay was higher than that of bacterial culture and pathological examination (p < 0.001, p < 0.001). The specificity of the mNGS assay was not statistically different from that of bacterial culture and pathological examination (p = 1.000, p = 1.000).

Conclusion

Data presented here demonstrated that mNGS can detect TB and non-TB bacteria simultaneously, with high sensitivity, specificity and short detection time. Compared with conventional detection methods, mNGS is a more rapid and effective diagnostic tool for suspected spinal TB.

Metagenomic next-generation sequencing assists the diagnosis treatment of fungal osteoarticular infections

Background

Fungal osteoarticular infection (FOI) is not commonly seen in clinical practice but proposes a great challenge to orthopedic surgeons. In this study, we aimed to investigate the risk factors, the clinical features, and surgical outcomes of FOI in our institution. Specifically, we aimed to explore the role of metagenomic next-generation sequencing (mNGS) in the diagnosis and treatment of FOI.

Methods

All the patients who were diagnosed and managed with FOI in our institution from January 2007 to December 2020 were retrospectively reviewed, including primary fungal implant-related infection, primary fungal osteomyelitis or arthritis, and fungal infections secondary to bacterial osteomyelitis or implant-related bacterial infections. The potential risk factors and the clinical and surgical features were analyzed. The pathogen data were compared between culture and the mNGS test.

Results

A total of 25 patients were included, namely, 12 primary implant-related infections, 7 primary fungal osteomyelitis or arthritis, and 6 fungal infections secondary to bacterial osteomyelitis or implant-related bacterial infections. Most cases had undergone multiple surgeries or long-term antibiotic treatment. Diagnosis was mainly based on microbial culture and the mNGS test. Optimization of culture methods and the use of mNGS assisted the diagnosis. Specifically, mNGS was performed in 12 patients, 5 of whom were culture-negative. In the remaining seven cases, mNGS demonstrated the same results as culture. Management of FOI was complicated as most patients required multiple surgeries followed by long-term antifungal treatment. In selected cases, antifungal-impregnated cement spacer retention can be an optional choice. The overall success rate was 100% (25/25) for our cohort.

Conclusion

We concluded that patients with comorbidities and a history of multiple surgeries or long-term antibiotics are under higher risk for FOI. Use of mNGS assists the diagnosis and treatment of FOI. Surgery combined with long-term antifungal treatment achieved satisfactory outcomes. In selected cases, antifungal-impregnated cement spacer retention can be an optional treatment choice.

Decisive diagnostic clue for infectious abdominal aortic aneurysm caused by Arthrobacter russicus in a diabetic elderly woman with renal dysfunction: A case report and literature review

Infectious aortic aneurysm (IAA) can be a rare but potentially fatal sequela of infectious inflammatory disease of the aortic wall with a high incidence of rupture. The definitive diagnosis is based on vascular imaging of the aneurysm using contrast-enhanced computed tomography (CE-CT) and identification of the causative microorganism from positive blood cultures (BCs). However, IAA remains extremely difficult to diagnose and treat in patients with prior antimicrobial treatment or with renal dysfunction. Here we describe a case of an 85-year-old woman with IAA caused by Arthrobacter russicus presenting with abdominal pain and fever that was initially diagnosed as a presumptive urinary tract infection and treated with empiric antimicrobial therapy. However, persistent abdominal pain with increased serological inflammation necessitated further evaluation. Unenhanced multimodality imaging considering the renal dysfunction revealed infectious aortitis of the infrarenal abdominal aorta, together with the initial culture results, leading to the tentative diagnosis of Klebsiella pneumoniae aortitis. Thereafter, serial monitoring with unenhanced magnetic resonance angiography (MRA) using thin-slab maximum intensity projection (TS-MIP) revealed acute aortic expansion strongly suggestive of a pseudoaneurysm that was successfully treated with early surgical repair under adequate infection control. Despite negative Gram staining and tissue culture results for the excised aortic wall, a definitive diagnosis of IAA secondary to A. russicus rather than K. pneumoniae was finally made by confirming the histologic findings consistent with IAA and the identification of A. russicus 16S rRNA on the resected aortic wall. The patient also developed a vascular graft infection during the postoperative course that required long-term systemic antimicrobial therapy. This case highlights the value of unenhanced MRA in the early detection of IAA in patients with renal dysfunction and the importance of a molecular diagnosis for identifying the causative microorganism in cases of culture- or tissue-negative IAA.

Evaluation of the metagenomic next-generation sequencing performance in pathogenic detection in patients with spinal infection

Spinal infection is a rarely occurred pathology, whose diagnosis remains a major challenge due to the low sensitivity of culturing techniques. Metagenomic next-generation sequencing (mNGS) is a novel approach to identify the pathogenic organisms in infectious diseases. In this study, mNGS technology was adopted for pathogenic detection in spinal infection from the tissue and pus samples. Additionally, the diagnostic performance of mNGS for spinal infection was evaluated, by comparing it with that of the conventional microbial culture, with the histopathological results as the gold standard. Overall, 56 samples from 38 patients were enrolled for mNGS testing, and 69 samples were included for microbial culture. 30 patients (78.95%) were identified to be positive by the mNGS method, which was higher than that of microbial culture (17, 44.74%). The sensitivity and specificity of mNGS with pus samples were 84.2% and 100.0%, respectively, which outperformed those of microbial culture (42.1% and 100.0%). The pathogen identification results were applied to medication guidance, and all 38 patients experienced favorable outcomes at three months, followed-up post-treatment, without any adverse effects. These findings proved that mNGS was superior to microbial culture in pathogenic identification of the spinal infection, thereby showing great promise in guiding drug administration and improving clinical outcomes.

Improved accuracy of etiological diagnosis of spinal infection by metagenomic next-generation sequencing

Currently, the use of metagenomic next-generation sequencing (mNGS), a new approach to identify organisms in infectious diseases, is rarely reported in the diagnosis of spinal infection. This study aimed to evaluate the potential value of mNGS in etiological diagnosis of spinal infection. In this retrospective study, the clinical data of patients with suspected spinal infection were collected by electronic medical records. Specimens obtained from each patient were tested via mNGS assay and other conventional microbiological tests (CMTs). The sensitivity and specificity of mNGS and CMTs were calculated using the final clinical diagnosis as the golden standard. In total, 108 patients were eligible for the study, with the mean length of stay of 42.8 days. Regarding the overall identification of pathogens, mNGS exhibited a better performance than CMTs, and several nontuberculous mycobacteria, fungi, and bacteria were newly discovered. In the diagnosis of spinal infection, the sensitivity, specificity, and area under the curve of mNGS were 90.72%, 81.82%, and 0.89, respectively, which were all higher than 52.17%, 56.25%, and 0.72 of the CMTs. At hospital discharge, the C-reactive protein, erythrocyte sedimentation rate, and white blood cell count of patients significantly decreased compared with hospitalization (all p < 0.05), and 88.89% showed good outcomes. These findings may suggest that mNGS has a better diagnostic accuracy in pathogenic identification of patients with suspected spinal infection, and patients treated with NGS-guided antimicrobial therapy mostly seem to have good outcomes.

The role of metagenomic next-generation sequencing in the pathogen detection of invasive osteoarticular infection

OBJECTIVE

This study aimed to analyzed the pathogenic bacteria spectrum in invasive and primary osteoarticular infection (IOI and POI), and compared the pathogen detection rate of metagenomic next-generation sequencing (mNGS) and microbial culture in IOI and POI.

METHODS

The suspected POI and IOI cases from 2008 to 2021 were included. The diagnosis of POI or IOI were made by at least two orthopaedic surgeons, two infectious diseases specialist and one senior microbiologist. Demographic characteristics, microbial culture results and so on were recorded. The pathogenic bacteria spectrum in IOI and POI were analyzed and the ability of mNGS and microbial culture in pathogen detection in IOI and POI were compared.

RESULTS

There were 63 POI cases and 92 cases, the common pathogen in POI and IOI were both Staphylococcus aureus. There are more cases with negative microbial culture results and multiple infections in IOI, and many cases were caused by rare and fastidious bacteria. The introduction of the mNGS could significantly increase the pathogen detection rate to 92.39% in IOI, which was 8.69% higher than that of microbial culture (P=0.007), while the improvement in POI was limited to about 2%.

CONCLUSIONS

mNGS was an ideal tool for IOI pathogen detection.

Utility of Metagenomic Next-Generation Sequencing for Etiological Diagnosis of Patients with Sepsis in Intensive Care Units

The performance of metagenomic next-generation sequencing (mNGS) was evaluated and compared with that of conventional culture testing in patients with sepsis. Prospective blood and bronchoalveolar lavage fluid (BALF) samples from 50 patients with sepsis were tested using cultures (bacterial, fungal, and viral) and mNGS of microbial DNA (blood and BALF) and RNA (BALF). mNGS had higher detection rates than blood culture (88.0% versus 26.0%, P < 0.001) and BALF culture (92.0% versus 76.0%, P = 0.054). RNA-based mNGS has increased the detection rate of several bacteria, fungi, and viruses, but not mycobacteria and Toxoplasma gondii. The number of multiple detections per specimen was higher in BALF (92.0%) than in blood (78.0%) samples, and the highest number of pathogens detected in a single specimen was 32. Among blood samples, compared to cultures, mNGS detected significantly more bacteria (P < 0.001), fungi (P = 0.012), and viruses (P < 0.001), whereas BALF mNGS had a higher detection rate for bacteria (P < 0.001) and viruses (P < 0.001). The percentage of mNGS-positive samples was significantly higher than that of culture-positive samples for several Gram-negative bacteria, some Gram-positive bacteria, and viruses, but not fungi. Mycobacteria had a higher detection rate by culture than by mNGS, but the difference was not significant due to the small sample size. The positive and negative agreements with 95% confidence intervals of mNGS and culture were 62.0% (50.4 to 72.7) and 96.8% (96.5 to 97.1), respectively. mNGS offers a sensitive diagnostic method for patients with sepsis and is promising for the detection of multipathogen infections. Clinical correlation is advised to interpret mNGS data due to the lack of unified diagnostic criteria.

IMPORTANCE Delays in effective antimicrobial therapy have resulted in decreased survival rates among patients with sepsis. However, current culture-based diagnostic methods have low sensitivity because of concurrent antibiotic exposure and fastidious and atypical causative organisms. Among patients with sepsis, we showed that mNGS methods had higher positive rates than culture methods, especially for bacteria, viruses, and multipathogen infections, which are difficult to culture and detect in patients treated with antibiotics. RNA-based mNGS has increased the detection rate of several bacteria, fungi, and viruses, but not mycobacteria and Toxoplasma gondii. mNGS also showed a high negative percent agreement with cultures. However, the interpretation of mNGS data should be combined with clinical data and conventional methods considering the lack of unified diagnostic criteria.

Pediatric Osteoarticular Infections Caused by Mycobacteria Tuberculosis Complex: A 26-Year Review of Cases in San Diego, CA

BACKGROUND

Osteoarticular infections (OAIs) account for 10%-20% of extrapulmonary Mycobacteria tuberculosis (MTB) complex infections in children and 1%-2% of all pediatric tuberculosis infections. Treatment regimens and durations typically mirror recommendations for other types of extrapulmonary MTB, but there are significant variations in practice, with some experts suggesting a treatment course of 12 months or longer.

METHODS

We conducted a retrospective review of children diagnosed with MTB complex OAI and cared for between December 31, 1992, and December 31, 2018, at a tertiary care pediatric hospital near the United States-Mexico border.

RESULTS

We identified 21 children with MTB complex OAI during the study period. Concurrent pulmonary disease (9.5%), meningitis (9.5%), and intra-abdominal involvement (14.3%) were all observed. MTB complex was identified by culture from operative samples in 15/21 children (71.4%); 8/15 (53.3%) cultures were positive for Mycobacterium bovis. Open bone biopsy was the most common procedure for procurement of a tissue sample and had the highest culture yield. The median duration of antimicrobial therapy was 52 weeks (interquartile range, 46-58). Successful completion of therapy was documented in 15 children (71.4%). Nine children (42.9%) experienced long-term sequelae related to their infection.

CONCLUSION

Among the 21 children with MTB complex OAI assessed, 8 of 15 (53.3%) children with a positive tissue culture had M. bovis, representing a higher percentage than in previous reports and potentially reflecting its presence in unpasteurized dairy products in the California-Baja region. Bone biopsy produced the highest culture yield in this study. Given the rarity of this disease, multicenter collaborative studies are needed to improve our understanding of the presentation and management of pediatric MTB complex OAI.

Optimization of Early Antimicrobial Strategies for Lung Transplant Recipients Based on Metagenomic Next-Generation Sequencing

The management of perioperative antibiotic options after lung transplantation varies widely around the world, but there is a common trend to limit antibiotic use duration. Metagenomic next-generation sequencing (mNGS) has become a hot spot in clinical pathogen detection due to its precise, rapid, and wide detection spectrum of pathogens. Thus, we defined a new antibiotic regimen adjustment strategy in the very early stage (within 7 days) after lung transplantation mainly depending on mNGS reports combined with clinical conditions to reduce the use of antibiotics. To verify the clinical effect of the strategy, we carried out this research. Thirty patients who underwent lung transplantation were finally included, whose information including etiology, antibiotic adjustment, and the effect of our strategy was recorded. Lung transplant recipients in this study were prescribed with initial antibiotic regimen immediately after surgery; their antibiotic regimens were adjusted according to the strategy. According to our study, the entire effectiveness of the strategy was 90.0% (27/30). Besides, a total of 86 samples containing donor lung tissue, recipient lung tissue, and bronchoalveolar lavage fluid (BALF) were obtained in this study; they were all sent to mNGS test, while BALF was also sent to pathogen culture. Their results showed that the positive rate of BALF samples was higher (86.67%) than that of donor’s lung tissue (20.0%) or recipient’s lung tissue (13.33%) by mNGS test, indicating BALF samples are more valuable than other clinical samples from early postoperative period to guide the early adjustment of antibiotics after lung transplantation. It is effective for mNGS combined with traditional methods and clinical situations to optimize antibiotic regimens in lung transplantation recipients within 7 days after surgery.

Diagnosis of vertebral osteomyelitis

Native vertebral osteomyelitis (NVO) is a potentially fatal infection which has seen a gradual increase in its incidence over the past decades. The infection is insidious, presenting with symptoms of back pain. Fever is present in about 60 % of patients. Prompt diagnosis of NVO is important to prevent the development of complications. Numerous laboratory and imaging tools can be deployed to accurately establish the diagnosis. Imaging techniques such as magnetic resonance, nuclear imaging, and computed tomography are essential in diagnosing NVO but can also be useful in image-guided biopsies. Laboratory tools include routine blood tests, inflammatory markers, and routine culture techniques of aspirated specimens. Recent advances in molecular techniques can assist in identifying offending pathogen(s). In this review, we detail the arsenal of techniques that can be utilized to reach a diagnosis of NVO.

Metagenomic Next-Generation Sequencing of Cerebrospinal Fluid for the Diagnosis of Cerebral Aspergillosis

Purpose: Cerebral aspergillosis (CA) is a rare but often fatal, difficult-to-diagnose, opportunistic infection. The utility of metagenomic next-generation sequencing (mNGS) for diagnosis of CA is unclear. We evaluated the usefulness of mNGS of the cerebrospinal fluid (CSF) for the diagnosis of CA. Methods: This prospective study involved seven consecutive patients with confirmed CA in whom CSF mNGS was performed. Serum (1→3)-β-D-glucan and galactomannan levels were determined, and histopathological examination and mNGS of the CSF were conducted. CSF specimens from three non-infected patients were used as positive controls. Results: mNGS of the CSF was positive in six of the seven confirmed CA cases (85.71% sensitivity). In the cryptococcal meningitis group (control), mNGS of the CSF was positive for Aspergillus in two patients (84.62% specificity). The positive likelihood ratio, negative likelihood ratio, and Youden's index of mNGS for CA in the CSF were 5.565, 0.169, and 0.7, respectively. Among the six mNGS-positive cases, more than two Aspergillus species were found in four (4/6, 66.67%). In the positive controls, the addition of one A. fumigatus spore yielded a standardised species-specific read number (SDSSRN) of 25.45 by mNGS; the detection rate would be 0.98 if SDSSRN was 2. Conclusion: mNGS facilitates the diagnosis of CA and may reduce the need for cerebral biopsy in patients with suspected CA. Trial Registration Number: Chinese Clinical Trial Registry, ChiCTR1800020442.

A metagenomics workflow for SARS-CoV-2 identification, co-pathogen detection, and overall diversity

An unbiased metagenomics approach to virus identification can be essential in the initial phase of a pandemic. Better molecular surveillance strategies are needed for the detection of SARS-CoV-2 variants of concern and potential co-pathogens triggering respiratory symptoms. Here, a metagenomics workflow was developed to identify the metagenome diversity by SARS-CoV-2 diagnosis (npositive = 65; nnegative = 60), symptomatology status (nsymptomatic = 71; nasymptomatic = 54) and anatomical swabbing site (nnasopharyngeal = 96; nthroat = 29) in 125 individuals. Furthermore, the workflow was able to identify putative respiratory co-pathogens, and the SARS-CoV-2 lineage across 29 samples. The diversity analysis showed a significant shift in the DNA-metagenome by symptomatology status and anatomical swabbing site. Additionally, metagenomic diversity differed between SARS-CoV-2 infected and uninfected asymptomatic individuals. While 31 co-pathogens were identified in SARS-CoV-2 infected patients, no significant increase in pathogen or associated reads were noted when compared to SARS-CoV-2 negative patients. The Alpha SARS-CoV-2 VOC and 2 variants of interest (Zeta) were successfully identified for the first time using a clinical metagenomics approach. The metagenomics pipeline showed a sensitivity of 86% and a specificity of 72% for the detection of SARS-CoV-2. Clinical metagenomics can be employed to identify SARS-CoV-2 variants and respiratory co-pathogens potentially contributing to COVID-19 symptoms. The overall diversity analysis suggests a complex set of microorganisms with different genomic abundance profiles in SARS-CoV-2 infected patients compared to healthy controls. More studies are needed to correlate severity of COVID-19 disease in relation to potential disbyosis in the upper respiratory tract. A metagenomics approach is particularly useful when novel pandemic pathogens emerge.

The clinical value of valve metagenomic next-generation sequencing when applied to the etiological diagnosis of infective endocarditis

Background

Metagenomic next-generation sequencing (mNGS) is widely applied in the etiological diagnosis of infectious diseases. However, the clinical practice of mNGS in infective endocarditis (IE) is relatively less studied. This research aimed to assess the etiological diagnostic value of valve mNGS in IE.

Methods

We retrospectively analyzed 49 IE patients who underwent cardiac valve surgery in Zhongshan Hospital, Fudan University, Shanghai from 1 June 2018 to 30 November 2020. Among these IE patients, 28 were culture positive and 21 were culture negative. The culture results of the culture-positive IE patients were set as gold standard to assess the sensitivity and specificity of valve mNGS in the etiological diagnosis of IE. We studied the positive detection rate of pathogens by valve mNGS among the culture-negative IE patients. During the same period, we also collected the resected valves of 8 patients with non-infective valvular diseases for mNGS as negative controls.

Results

The valve mNGS results of the culture-positive IE patients were the exact same as their culture results. Both the sensitivity and specificity of valve mNGS were 100%. The positive detection rate of pathogens by valve mNGS was 100% among the culture-negative IE patients. The stringent mapped reads number of genera (SMRNG), relative abundance of genera, stringent mapped reads number of species (SMRN), relative abundance of species, and coverage rate of valve mNGS results were significantly higher in culture-positive IE participants than in culture-negative IE participants. The valve mNGS results of the 8 participants with non-infective valvular diseases were all negative.

Conclusions

Valve mNGS is a promising technology for the etiological diagnosis of IE, especially culture-negative IE, and it may be used to guide precise antibiotic treatment after surgery.

Spondylitis following bloodstream dissemination of Mycobacterium chelonae disseminated in an immunocompetent patient: a case report and literature review

Non-tuberculous mycobacterial spondylitis is a rare spinal infection, especially among patients without acquired immunodeficiency syndrome or other immune impairments. Because of its rarity and non-specific clinical manifestations, diagnosis is often delayed or missed. Here, we present a case of Mycobacterium chelonae spondylitis in an immunocompetent patient and review the relevant literature.

Use of Metagenomic Next-Generation Sequencing to Identify Pathogens in Pediatric Osteoarticular Infections

BACKGROUND

Osteoarticular infections (OAIs) are frequently encountered in children. Treatment may be guided by isolation of a pathogen; however, operative cultures are often negative. Metagenomic next-generation sequencing (mNGS) allows for broad and sensitive pathogen detection that is culture-independent. We sought to evaluate the diagnostic utility of mNGS in comparison to culture and usual care testing to detect pathogens in acute osteomyelitis and/or septic arthritis in children.

METHODS

This was a single-site study to evaluate the use of mNGS in comparison to culture to detect pathogens in acute pediatric osteomyelitis and/or septic arthritis. Subjects admitted to a tertiary children's hospital with suspected OAI were eligible for enrollment. We excluded subjects with bone or joint surgery within 30 days of admission or with chronic osteomyelitis. Operative samples were obtained at the surgeon's discretion per standard care (fluid or tissue) and based on imaging and operative findings. We compared mNGS to culture and usual care testing (culture and polymerase chain reaction [PCR]) from the same site.

RESULTS

We recruited 42 subjects over the enrollment period. mNGS of the operative samples identified a pathogen in 26 subjects compared to 19 subjects in whom culture identified a pathogen. In 4 subjects, mNGS identified a pathogen where combined usual care testing (culture and PCR) was negative. Positive predictive agreement and negative predictive agreement both were 93.0% for mNGS.

CONCLUSIONS

In this single-site prospective study of pediatric OAI, we demonstrated the diagnostic utility of mNGS testing in comparison to culture and usual care (culture and PCR) from operative specimens.

Diagnosis of Mycobacterium tuberculosis Septic Shock in Patients With Anti-synthetase Syndrome Based on Next-Generation Sequencing: A Case Report and Literature Review

A 51-year-old woman was transferred to the intensive care unit with such symptoms as fever, swollen left knee joint, pain and hypotension. After preliminary evaluation, she was diagnosed as suffering acute suppurative arthritis and septic shock. Then, she was rescued and prescribed to receive treatment with broad-spectrum antibiotics. However, there was no source of infection identified except for the knee joint. The bacterial and fungal cultures of blood samples and articular effusion were shown to be negative, while the results obtained from the next-generation sequencing of blood and articular effusion revealed that Mycobacterium tuberculosis was positive. The patient was then put on five combinations of anti-tuberculosis therapeutic treatment. Nevertheless, despite the active anti-tuberculosis treatment put in place, her general condition still deteriorated progressively. As the level of her bilirubin continued to rise, further treatment was affected, which prompted the change made to the anti-tuberculosis treatment program. Her clinical condition continued to deteriorate, which led to the development of unstable vital signs and the multiple organ dysfunction syndrome. In spite of our best efforts to save her life, the patient still ended up with death.

Molecular sequencing technologies in the diagnosis and management of prosthetic joint infections

INTRODUCTION

Prosthetic joint infections (PJIs) can be challenging to eradicate and have high morbidity and mortality. Current microbiology culture methods can be associated with a high false-negative rate of up to 50%. Early and accurate diagnosis is crucial for effective treatment, and negative results have been linked to a greater rate of reoperation.

AREAS COVERED

There has been increasing investigation of the use of next-generation sequencing (NGS) technology such as metagenomic shotgun sequencing to help identify causative organisms and decrease the uncertainty around culture-negative infections. The clinical importance of the organisms detected and their management, however, requires further study. The polymerase chain reaction (PCR) has shown promise, but in recent years multiple studies have reported similar or lower sensitivity for bacteria detection in PJIs when compared to traditional culture. Furthermore, issues such as high cost and complexity of sample preparation and data analysis are to be addressed before it can move further toward routine clinical practice.

EXPERT OPINION

Metagenomic NGS has shown results that inspire cautious optimism - both in culture-positive and culture-negative cases of joint infection. Refinement of technique could revolutionize the way PJIs are diagnosed, managed, and drastically improve outcomes from this currently devastating complication.